diff --git a/nix/devshell.nix b/nix/devshell.nix
index 9846fac88..a6e3d2355 100644
--- a/nix/devshell.nix
+++ b/nix/devshell.nix
@@ -2,6 +2,7 @@
 
 , gdb
 , glxinfo
+, parallel
 , pkg-config
 , scdoc
 , tracy
@@ -31,6 +32,7 @@
 
     # Testing
     gdb
+    parallel
     tracy
     vttest
   ];
diff --git a/test/run-all.sh b/test/run-all.sh
index be660f27f..77beb344a 100755
--- a/test/run-all.sh
+++ b/test/run-all.sh
@@ -18,9 +18,9 @@ find ${DIR}/cases \
   -type f \
   -name '*.sh' | \
   sort | \
-  xargs \
-    -I '{}' \
-    ${DIR}/run-host.sh \
+  parallel \
+  --will-cite \
+  ${DIR}/run-host.sh \
     --case '{}' \
     --rewrite-abs-path \
     $@
diff --git a/test/run.sh b/test/run.sh
index 4dd53f95d..641dc6943 100755
--- a/test/run.sh
+++ b/test/run.sh
@@ -71,7 +71,10 @@ fi
 
 # NOTE: This is a huge hack right now.
 if [ "$ARG_EXEC" = "ghostty" ]; then
-  ARG_EXEC="/src/ghostty";
+  ARG_EXEC="/tmp/ghostty";
+
+  # Copy so we don't read/write race when running in parallel
+  cp /src/ghostty ${ARG_EXEC}
 
   # We build in Nix (maybe). To be sure, we replace the interpreter so
   # it doesn't point to a Nix path. If we don't build in Nix, this should